Hyper-Rayleigh light scattering

Kaatz, P. and Shelton D.P., Polarized hyper-Rayleigh light scattering measurements of nonlinear optical chromophores. J. Am. Chem.SOc. (1996) 105 3918-3929. 

T. Bancewicz and S. Kielich. Intermolecular interaction effect on the line shape of hyper-Rayleigh light scattering by molecular liquids. Molec. Phys., 57 615-627 (1976). 

W. Glaz, T. Bancewicz, J.-L. Godet, G. Maroulis, A. Haskopoulos, Hyper-Rayleigh light-scattering spectra determined by ab initio collisional hyperpolarizabilities of He-Ne atomic pairs. Phys. Rev. A 73(4), 042708 (2006)... 

Abstract Second-order nonlinear light scattering, or hyper-Rayleigh scattering (HRS)... 

Figure 4. Open circles, angular dependence of the second-order scattered light intensity (hyper-Rayleigh scattering from 1064 to 532 nm) for a suspension of purple membrane patches of bacteriorhodopsin before any solubilization has taken place. Solid curve best fit to the data by combining the nonlinear hyperpolarizability of retinal with the linear refractive index of the upo-protein.

The important question in EFISHG, especially in the light of the complementarity with hyper-Rayleigh scattering (HRS), is What is actually experimentally determined The expression for the rotational contribution is determined by the scalar product of the dipole moment vector with the vector part of the third-rank hyperpolarizability tensor (Eq. (13)). 

A second experimental method, Hyper-Rayleigh Scattering (HRS), allows (3 measurements for nondipolar and/or ionic molecules, which cannot be measured with the standard EFISH, The intensity of the scattered light is proportional to the square of the incident intensity and can be written as... 

Experimentally, mainly two techniques - the electric field induced second harmonic generation (EFISH) and hyper-Rayleigh scattering (HRS, also termed harmonic light scattering method) - are used in order to determine in solution the experimental value of the quadratic hyperpolarizability of molecular NLO chromophores. 

Hyper-Rayleigh and hyper-Raman scattering can be described by extending the linear relation (2.1) between the induced oscillating electric dipole moment and the electric field of the light wave to include higher-order terms ... 

At present, in spite of the well-known fact that the interaction of atoms and molecules leads to the changing of their multipole moments and (hyper)polariz-abilities [1-3], only the simple moments and polarizabilities of interacting molecules such as interaction-induced dipole moments and dipole polarizabilities have widely studied. Nevertheless, the induced dipole moments and polarizabilities play the important role in understanding the collision-induced absorption, collision-induced Rayleigh scattering or collision-induced Raman light scattering [4-9],... 

The hyper-Rayleigh scattering when the incident light has linear polarization may be described by the two tensor invariants of the quadratic hyperpolarizability [3, 62, 63] (in the general case there are six rotation invariants of / [63])... 

Then, for the hyper-Rayleigh scattering directed at 90° to the propagation of incident light the intensity (I) of the scattered light and its degree of depolarization (p) take the form [62]... 

Clays and Persoons presented a new technique in 1992 for the determination of the hyperpolarizabilities of nonlinear optical compounds in solution using the hyper-Rayleigh scattering (HRS). The values for first hyperpolarizabilities can be obtained from second-order scattered light intensity. This method has several advantages over the EFISH technique it needs no electric field, and thus the experiment is simplified, the hyperpolarizability P can be directly measured, and the P values for salts can be determined as weU. 

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